Abstract: A power transmission apparatus for a vehicle which includes a first, a second, and a third rotor which split power among a motor-generator, an internal combustion engine, and a driven wheel of the vehicle. The apparatus also includes a torque transmission control mechanism which selectively transmits torque between the first rotor and the engine. When the torque transmission control mechanism establishes the transmission of torque between the first rotor and the engine, powers, as produced by the second and third rotors, are opposite in sign to each other. This enables the speed of the first rotor to be set to zero (0) or a very low speed. Therefore, when an initial torque is applied to the engine through the first rotor to start the engine, the mechanical vibration which usually arises from the application of initial torque and is to be exerted on the power transmission apparatus is minimized.

Abstract: A power transmission apparatus for a vehicle is provided which is equipped with a power split device and a speed variator. The power transmission device is designed to set a speed ratio of speed of rotation of an output of a power source to speed of rotation of a driven wheel in a power circulation mode of a power split device to lie within one of a positive range in which a sign of the speed ratio is positive and a negative range in which a sign of the speed ratio is negative. This results in a decrease in degree of torque acting on the speed variator such as a continuously variable transmission, thus permitting a required degree of durability of the speed variator to be reduced.

Abstract: A power transmission apparatus for a vehicle is provided which is equipped with a power split device and a speed variator. The power transmission device is designed to set a speed ratio of speed of rotation of an output of a power source to speed of rotation of a driven wheel in a power circulation mode of a power split device to lie within one of a positive range in which a sign of the speed ratio is positive and a negative range in which a sign of the speed ratio is negative. This results in a decrease in degree of torque acting on the speed variator such as a continuously variable transmission, thus permitting a required degree of durability of the speed variator to be reduced.

Abstract: A power transmission device includes a planetary gear set and a first and a second connecting mechanism. The planetary gear set receives power from a power source and outputs it to a power-driven member. The first connecting mechanism connects a first and a second rotor of the planetary gear set through a separate path. The second connecting mechanism connects the second rotor and a third rotor of the planetary gear set through a separate path. The controller is operable selectively in a first operation mode in which the second connecting mechanism is engaged, while the first connecting mechanism is disengaged and a second operation mode in which the second connecting mechanism is engaged, while the first connecting mechanism is disengaged. This ensures suitable mechanical connections among the power source, the power-driven member, and the power split mechanism which match with an operating condition of the power transmission device.

Abstract: A power transmission apparatus for a vehicle which includes a first and a second planetary gear set to transmit power to a driven wheel. A ring gear of the first planetary gear set is coupled to the driven wheel. A carrier of the first planetary gear set is coupled to a ring gear of the second planetary gear set. A carrier and a sun gear of the second planetary gear set are so linked as to have signs of power which are opposite each other. A sign of speed of the ring gear of the second planetary gear set is reversed under the condition that the a sign of speed of a motor-generator is fixed, thereby reversing the sign of speed of the carrier of the first planetary gear set, which eliminate the circulation of power between the sun gear and the carrier of the first planetary gear set.

Abstract: An in-vehicle power transmission apparatus is equipped with a motor-generator working as an engine to drive a vehicle and a power split device made up of a plurality of power split rotors. A first one of the rotors is coupled to a driven wheel of the vehicle, while a second one of the rotors is coupled to an accessory such as an air compressor of an air conditioner. The speed of the second rotor is controllable independently of that of the driven wheel. This eases restrictions on the supply of power produced by the generator-motor to the accessory. Alternatively, the rotors are so linked that when the speed of the first rotor is not zero (0), the speed of the second rotor has one of zero (0) and a value other than zero (0), thus ensuring the stability in supplying the power to drive the vehicle to the accessory.

Abstract: After an engine starts, a rotation speed of the engine is fed back to a target rotation speed that is defined in response to requested power for the engine. In addition, by operating a gear ratio of a CVT, a rotation speed of an output side of a one-way bearing is fed back to the target rotation speed.

Abstract: A power transmission apparatus for a vehicle is provided which is equipped with a power split device and a speed variator. The power transmission device is designed to set a speed ratio of speed of rotation of an output of a power source to speed of rotation of a driven wheel in a power circulation mode of a power split device to lie within one of a positive range in which a sign of the speed ratio is positive and a negative range in which a sign of the speed ratio is negative. This results in a decrease in degree of torque acting on the speed variator such as a continuously variable transmission, thus permitting a required degree of durability of the speed variator to be reduced.

Abstract: A power transmission apparatus for a vehicle which includes a first and a second planetary gear set to transmit power to a driven wheel. A ring gear of the first planetary gear set is coupled to the driven wheel. A carrier of the first planetary gear set is coupled to a ring gear of the second planetary gear set. A carrier and a sun gear of the second planetary gear set are so linked as to have signs of power which are opposite each other. A sign of speed of the ring gear of the second planetary gear set is reversed under the condition that the a sign of speed of a motor-generator is fixed, thereby reversing the sign of speed of the carrier of the first planetary gear set, which eliminate the circulation of power between the sun gear and the carrier of the first planetary gear set.

Abstract: A power transmission apparatus for a vehicle which includes a first, a second, and a third rotor which split power among a motor-generator, an internal combustion engine, and a driven wheel of the vehicle. The apparatus also includes a torque transmission control mechanism which selectively transmits torque between the first rotor and the engine. When the torque transmission control mechanism establishes the transmission of torque between the first rotor and the engine, powers, as produced by the second and third rotors, are opposite in sign to each other. This enables the speed of the first rotor to be set to zero (0) or a very low speed. Therefore, when an initial torque is applied to the engine through the first rotor to start the engine, the mechanical vibration which usually arises from the application of initial torque and is to be exerted on the power transmission apparatus is minimized.

Abstract: A power transmission device includes a planetary gear set and a first and a second connecting mechanism. The planetary gear set receives power from a power source and outputs it to a power-driven member. The first connecting mechanism connects a first and a second rotor of the planetary gear set through a separate path. The second connecting mechanism connects the second rotor and a third rotor of the planetary gear set through a separate path. The controller is operable selectively in a first operation mode in which the second connecting mechanism is engaged, while the first connecting mechanism is disengaged and a second operation mode in which the second connecting mechanism is engaged, while the first connecting mechanism is disengaged. This ensures suitable mechanical connections among the power source, the power-driven member, and the power split mechanism which match with an operating condition of the power transmission device.

Abstract: An in-vehicle power transmission apparatus is equipped with a motor-generator working as an engine to drive a vehicle and a power split device made up of a plurality of power split rotors. A first one of the rotors is coupled to a driven wheel of the vehicle, while a second one of the rotors is coupled to an accessory such as an air compressor of an air conditioner. The speed of the second rotor is controllable independently of that of the driven wheel. This eases restrictions on the supply of power produced by the generator-motor to the accessory. Alternatively, the rotors are so linked that when the speed of the first rotor is not zero (0), the speed of the second rotor has one of zero (0) and a value other than zero (0), thus ensuring the stability in supplying the power to drive the vehicle to the accessory.